Danielle Keller, a graduate student in the Curriculum for the Environment and Ecology, has been awarded a National Science Foundation Graduate Research Fellowship to pursue her studies under the direction of her faculty advisor, Dr. F. Joel Fodrie.
Danielle is interested in understanding the structure and function of estuarine ecosystems and communities. Her work focuses on using two model ecosystems, oyster reefs and salt marshes, to explore the dynamics of landscape effects on marine community assemblages. She would like to develop general predictions about what drives secondary production in ecosystems (e.g. prey availability, refuge space, density dependence, or connectivity). Additionally she would like to quantify the effects of human impacts (e.g. increased development and overharvest) on ecosystem service delivery. She seeks to understand how restoration can mitigate the losses of supporting services, such as nursery habitats and biodiversity, and provisioning services, such as recreational and commercial fisheries, offered by these ecosystems.
Danielle began her research career as an undergraduate student at the University of Florida working in Dr. Brian Silliman’s salt marsh community ecology laboratory. She received a B.S. in Wildlife Ecology from the University of Florida, where she wrote a senior thesis on the effects of alligator presence on blue crab foraging and behavior. She spent some time after graduation working as a technician at the UNC Institute for Marine Sciences with Drs. Joel Fodrie and Charles Peterson. She is currently drafting a manuscript discussing whether restored/artificial habitat subsidies in estuarine waters function to enhance fish production or simply to attract and redistribute existing fishes.
Her NSF GRFP Award is entitled “Intraguild predator behavior facilitates a foundation species.” Due to the global loss (~85%)of oyster reefs (a foundation species) and the strong impacts species interactions among this habitat may have on its survival, the primary goal of this study is to investigate how interactions between two oyster predator species (stone crabs and sheepshead fish) affects the fitness of oysters. Stone crabs excavate burrows in oyster reefs as a source of refuge from predators, while their prey consist of small consumers such as crustaceans and oysters. Sheepshead fish, on the other hand, are highly mobile predators, which rely on reefs mainly as a prey source of oysters themselves and juvenile consumers (crustaceans, including juvenile stone crabs). Danielle’s previous observations of stone crab territoriality over burrows (homes) suggest a negative effect on sheepshead feeding behavior. She hypothesizes this limitation of oyster consumption will have a net positive effect on the reef growth and structural complexity over time. Having a structurally complex reef with many nooks and crannies limits predation and allows for a greater biomass and diversity of resources (ribbed mussels, barnacles, tunicates) along with increased densities and fitness of juvenile consumers (mainly crustaceans including stone crabs). Managers can use these species interaction impacts to manage the health and performance of foundation species in an ecosystem-based approach.